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Home made tube mount rings


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I've just made one mount ring for my 80mm refractor and just wondering if anyone can give some advice.

I made the ring from 30mm X 3mm aluminium flat bar and after successfully managing to break two pieces of aluminium I decided to do some online research to prevent stress fractures (embarrassing for someone with engineering fabrication qualifications (glorified welder)).

Here's some pictures of the first ring which I'm sure should be a little larger diameter but I can still slip some felt in to protect the tube.





I know, it doesn't look completely square (round) but it sits flat and aligns fine. I had to work out some major bugs in my process and the next one will be as near to perfect as I'm going to get. My process has been refined for the next one so it should be much better.

There will eventually be a locking bolt across the top to tension the two sides.

There's no stress fractures in any bends and I would like an opinion on suitability before I spend considerable hours making the second. If it's not deemed suitable by the knowledgeable members here I will scrap the idea and come up with another brilliant (??) plan.

I need the rings to mount my tube on a dovetail plate for my new EQ3.


Edited by Leo.A
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Yes, it is a CX. I have owned 2 of them, still have one 81 model with genuine 39000 Ks on the clock and a spare frame and engine. The most reliable bike I have ever owned.

Edited by Leo.A
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  • 2 weeks later...

I finished my rings but haven't fully assembled the tube assembly yet till I get hold of a new crayford 2" focuser. Not easy with an ID on the tube of 80mm.

I still have to pick up a slightly longer adjustment bolt (got hundreds somewhere).



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Morning Leo.

Aluminium does not like being bent at tight angles and by the look of your photos you are folding yours in a vice.

To open out the fold radius I would suggest you fold the next ones round a small diameter bar about 10mm dia should do the trick.

Place the bar in the top of the vice jaws between the jaw and the aluminium. Roll the aluminium around the bar and it will stop the stress fracture caused by trying to fold it around the 90 degree edge of the vice jaw.

Happy manufacturing.


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Thanks Graham!

I actually folded them around a piece of 1" gal box section with a rolled (round) edge and carefully checked to see they don't have any visible, major stress fractures.

After breaking my first two attempts I checked out how to do it and these seem OK.

The curvature isn't really obvious in the photos because of the angle of the shot, but they are round edges 8mm diameter roll.

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